Light-sensitive photographic materials



United States Patent 01 lice 3,502,476 Patented Mar. 24, 1970 US. C]. 9690 7 Claims ABSTRACT OF THE DISCLOSURE A composition contains a compound capable of producing .free radicals upon exposure to light and an organic compound which reacts with the said free radicals to produce a color change. The free radicals progenitors are halogenated organic sulfoxides or sulfone compounds.

This invention relates to light-sensitive, photographic materials including both the printing-out and bleachingout types. More particularly, this invention relates to a light-sensitive, photographic material comprising a photoactivator capable of generating a free radical by the action of light and a color modifier capable of showing a visible color change by the action of said free radical, said photo-activator being a halogenated organic sulfoxide or sulfone compound of the below-mentioned general formula. It is a principal object of the invention to provide a light-sensitive, photographic material having good stability, non-toxic processibility, excellent sensitiveness and good tone quality.

In the known light-sensitive, photographic material of the above-indicated type, halogenated hydrocarbons are commonly used as photo-activators, among which carbon tetrabromide and aroyl trihalogenated hydrocarbons are particularly preferred. The photographic material made of carbon tetrabromide, however, suifers from a serious disadvantage, that is, very poor stability because of the dissipation of the carbon tetrabromide from the material due to its high volatility. For example, such photographic material as made of carbon tetrabromide is so unstable that it may become useless within several days after its preparation. Furthermore, carbon tetrabromide vapor is very toxic and so that environment for workers should be kept below 1 ppm. of the carbon tetrabromide (cf. F.M. Turner, Atomic Energy Res. Estab. Great Brit. MED/M-Zl, 1958). Accordingly, it is necessary to take a special care for avoiding respiration of the toxic vapor during handling of the material. Aroyl halogenated hydrocarbons are less volatile than carbon tetrabromide. However, they have severe lachrymatorines and so it is necessary to take a care in order to avoid inhalation of the resulting vapor during thermal fixing.

In accordance with the present invention, a halogenated organic sulfoxide or sulfone compound of the general formula (wherein X is hydrogen, chlorine or bromine; Y is hydrogen, chlorine or bormine; Z is chlorine or bromine; and

R is non-substituted or substituted aryl group, heterocyclic group or a group in which R R and R individually are hydrogen, chlorine or bromine) is employed as a photo-activator thereby overcoming all the disadvantages encountered in the prior art.

All the compounds represented by the above-indicated general formula are crystalline and do not show such volatility as carbori tetrabromide has. Therefore, a light-sensitive photographic material of the present invention which contains the above-specified compound is very stable because of its being free from dissipation of the photoactivator. Further, this material is entirely non-toxic and does not raise any lachrymatory vapor, and so it can be handled without any special care. The light-sensitive photographic material advantageously has high sensitiveness and good tone quality in comparison with those of any known photographic material. For instance, the photographic material of the present invention can give more sharp color tone even when the same color modifier as in the known photographic material is used.

Typical compounds useful as photo-activators in the present invention will be listed below. It is, however, to be noted that they are merely illustrative and do not limit the scope of the invention.

( 1) Hexabromodimethyl-sulfoxide M.P. C:

M.P. 117 C.

1'8 (4) Trichloromethyl-phenyl-sulfone (5) Tribr0momethyl-phenyl-sulfone (6) Trichloromethyl-p-chlorophenyl-sulfone (7) Tribrmomethyl-p-nitrophenyl-sulfone Tetrabromodimethyl-sulfone O CHBrz (decomp) (1 l) 2,4-dichlorophenyl-trichloromethyl-sulfone 12) 2-methyl-4-chlorophenyl-trichloromethyl-sulfone Cl CH M.P.100 o.

( l3) 2,S-dimethyl-4-chlorophenyl-trichloromethylulfone S-COl; I g M.P. 150C. 01

(14) 2,4-dichlorophenyl-tribromomethyl-sulfone M.P. 132C.

( 15) Bromomethyl-dibromomethyl-sulfone O OHzBr s M.P. 67C. 0 CHBrz These compounds can be obtained with ease by bringng the corresponding thioglycolic acid derivative into 'eaction with an aqueous sodium hypochlorite or hypo- )romite solution at a temperature of to 40 C. The :tarting material to be used is rather cheap and the abovenentioned procedures for preparation are simple. The :ompounds thus prepared can generate an active halogen free radical which will cause a visible color change in *espect to a color modifier, when these compounds are exaosed to light, particularly ultraviolet ray. Those which :ontain a nitrophenyl or chlorophenyl group in their tructure are particularly advantageous, because they are :ensitive over the broad range of spectrum covering light )f a long wave length.

M.P. 201 C.

M.P. 142 C.

M.P. 150 C.

M. P. 160-162 C.

M.P. 98 C.

Color modifiers, which can provide a visible color change by the action of a free radical resulting from a photo-activator, can be classified in two types. Those of the first type are such inherently colorless materials which can be converted to the colored state by the action of a free radical. Those of the second type are such inherently colored materials whose color can be changed to another color or can be decolorized by the action of a free radical. A light-sensitive photographic material using a color modifier of the former type can be employed in so-called nega-posi system since said material which is originally colorless develops color on the action of light. On the other hand, a light-sensitive photographic material using a color modifier of the latter type is using in so-called posi-posi system. Typical color modifiers of the first type include aryl amines. In addition to simple aryl amines, socalled Leuco dyes which are aminoor substituted aminobearing dyes in reduced form can be used. Typically are included the following: Diphenyl amine, dibenzyl amine, triphenyl amine, N,N-diethyl aniline, N,N-dimethyl aniline, N-hydroxy-N-ethyl aniline, dibenzyl aniline, oaminodiphenyl amine, p hydroxydiphenyl amine, N- vinyl carbazole, 2-phenyl indolidine, N,N-dihydroxyethyl aniline, N,N-diphenyl-p-phenylene diamine, N,N-dihydroXyethyl-m-toluidine, oz-naPhthYl amine, p-dimethylamino-benzaldehyde, 3-aminoquinoline, indole, salicylidene-p-toluidine, salicylidene-p-chloroaniline, cyanomethylene 4 quinolyl-Z-naphthalene, 3-phenyl-indole, a-diethylamino-pyridine, p,p-methylene bis-aniline, p,p'- methylene bis (N,N-dimethylaniline), p,p'-benxylidine bis-(N,N-dimethylaniline), p,p',p-methylidine tris-(N, N diethylaniline), p,p hydroxymethylene bis(N,N-dimethylaniline), p,p' (dimethylamino) diphenyl amine, p,p-aminomethylene-bis (N,N-dimethylaniline p,p- (0"- chlorobenzylidene) bis(N,N-dimethylaniline), p,p'-(p"- aminobenzylidene) bis aniline, p,p' (p" amino-m"- methylbenzylidene) bis (N-phenylaniline) 1,1-bis(p-dimethylaminophenol)-p-dimethylaminophthalein, 3,6-bis (diethylamino) spiro(phthalein-1,9-Xanthene) 3,6-bis diethylamino) 9 (p dimethylaminophenol)Xanthene, 1,1 bis(p dimethylaminophenol) p dimethylaminophthalane, 1,1 bis(p aminophenol) p aminophenolphthalane, 10 benzoyl 3,7-di(p-dimethylamino) -phenothiazine, 10 cinnamoyl-3,7-di(p-dimethylamino)-phenothiazine, 3-diethylamino-7-aminophenoxazine, etc. Other color modifiers effective for use in the nega-poSi system are the quarternary salts and N-oxides of nitrogen-containing heterocyclic compounds. Typical examples include the quarternary salts of Z-methylbenzthiazole methyl iodide, 2-methylbenzthiazole ethyl bromide, quinardine methyl iodide, 2,S-dimethyl-benzthiazole methyl-p-tolnenesulfonate and 2,5,6-trimethylbenzthiazole butyl iodide, as well as 4-methylquinoline N-oxide, 2,2-dipyridine N- oxide disulfide and quinoline N-oxide. Sometimes these N-oxide compounds are preferable used because they can show some sensitizing efi'ect.

Color modifiers which can be effectively used in the posi-posi system include a variety of dyes, e.g. diphenyl methane dyes, triphenyl methane dyes, thiazine dyes, oxazine dyes, Xanthene dyes, anthraquinone dyes, iminonaphthoquinone dyes, azomethine dyes, etc. Typical examples are Orlamin (Cl. 41000), Victoria Blue (Cl. 44045), Victoria Blue R (Cl. 44040), Brilliant Lowdurine Blue (CI. 42565), Benzoyl Methylene Blue, Cinnamoyl Methylene Blue, p-Anisoyl Methylene Blue, New Methylene Blue (C.I. 51195), Nile Blue A (CI. 51180), Ephitenew Blue (CI. 51185), Rhodamine B (C.I. 45170), Rhodamine 3B (-C.I. 45175), Rhodamine 12 GM (CI. 45310), Sudan Brau G (CI. 61525), Sudan Blue GN (C.I. 61520), Celliton Blue (CI. 64500), 4-p-diethylaminophenylimino naphthoquinone, 2 carboxyanilino 4 pdiethylaminophenylimino-naphthoquinone, Z-carbostearylamino 4 p dihydroxyethylaminophenylimino naphmethylphenylimino acetanilide, cyano p diethylaminothoquinone, p methoxybenzoyl p diethylamino ophenylimino acetanilide, 1 phenyl 3 methyl 4 pdiethylaminophenylimino 5 pyrazolone, 1 8 naphthyl 3 methyl 4 p diethylaminophenylimino 5- pyrazolone, etc.

A light-sensitive, photographic material of the present invention can be prepared by coating a solvent solution comprising the above-mentioned photo-activator and color modifier together with an appropriate film-forming polymeric binder on a support (e.g. paper, film base, etc.) and then drying. Suitable binders include cellulose derivatives, e.g. acetyl cellulose, acetyl butyryl cellulose, ethyl cellulose, etc.; vinyl polymers or copolymers, e.g. polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyacrylic esters, polystyrenes, styrene-maleic anhydride copolymer, etc.; and synthetic rubbers, e.g. cyclized rubber, acryl rubber, butadiene copolymers, etc.

A light-sensitive photographic material of the invention can produce an image on its light-sensitive side through a visible color change caused by the action of a free radical resulting from the photo-activator when the said photographic material is subjected to imagewise exposure to light. Light sensitiveness of such photographic material can be increased by addition of a sensitizer. Suitable sensitizers can be classified into two groups, one of which belongs to so-called optical sensitizers capable of broadening the sensible wave length region of the light-sensitive photographic material to cover a visible light region and the other is a chemical sensitizer capable of increasing light sensitiveness independently from the sensible wave length region. The sensitizers of the former group may be sensitizing dyes known in the photographic arts, e.g. acridine dyes, cyanine dyes, mellocyanine dyes, styryl dyes, etc. Typical dyesutifs are Acridine Orange, Acridine Red, Rose Bengal, Methylene Blue, Pinacyanol, Pinacryptol Yellow, 1- 3 -ethyl-2 (3H) -benzothiazolidine) 4-butylidene-di-benzothiazolyl methane, 1-ethyl-4-( 1H quinolidene)-ethylidene-di-Z-benzothiazolyl methane, 5-2- (3 ethylbenzoxazolidene) ethylidene 2 phenylimido- 3 phenyl 4 keto tetrahydrothiazole, 1,3 diethylthia 4' carbocyanine iodide, 1,3 dimethyl oxa 2- carbocyanine p toluenesulfonate, 5 1 methyl 2(1H)- quinolidene 2 butylidene 3 ethyl 2 thio 2,4 oxazolidenedione, etc. Useful as the sensitizers of the second group are the following aldehydes: benzaldehyde, dimethylaminobenzaldehyde, ortho-phthaldialdehyde, salicylaldehyde, thiosalicylaldehyde, anisaldehyde, vanilline, phenylacetaldehyde, o-chlorobenzaldehyde, ascorbic acid, benzaldehyde sulfonate, etc. 4-Methylquinoline N-oxide, 2,2'-dipyridine N-oxide disulfide and quinoline N-oxide also are useful. By suitable use of these sensitizers, it is possible to have light sensitiveness increased by 2 to 20 times.

A thermal fixing agent is the preferred component to be compounded with a sensitizer. A light-sensitive, photographic material of the present invention is subjected to fixation by heating or solvent treatment after printing. In a case of thermal fixation being employed, incorporation of a thermal fixing agent will enhance fixing effect so as to provide a more stable image..Suitable thermal fixing agents are phthalic anhydride, maleic anhydride, succinic anhydride and other anhydrides, and benzoic acid, phenylacetic acid, phenoxyacetic acid, phthalaldehydic acid, palmitic acid, stearic acid and other organic acid. These thermal fixing agents may be added to a binder solution containing the photoactivator and color modifier. In addition to the above-specified acids or anhydrides, some salts including sodium diethyl-dithiocarbamate, sodium sulfite, sodium metaborate, sodium carbonate, sodium salicylate, sodium oxalate, etc. also are effective as thermal fixing agents. However, these salts can not be added directly to the binder solution and they should be prepared as a separate OJ-5% aqueous solution which is then overcoated onto the light-sensitive layer of a light-sensitive, photographic material of the present invention.

A light-sensitive, photographic material of the invention, as stated previously, can be prepared by dissolving the above-mentioned various ingredients into a binder solution and then applying the resulting solution to a suitable support in the manner known in the art. The weight proportions of these ingredients as required are as follows:

Parts Solvent 500-1,000 Film-forming binder 1 20-100 Photo-activator 1-50 Color modifier 10-100 Thermal fixing agent (optional) 5-10 Sensitizer (optional) l-5 The amount of binder should be as most 10% based on the Weight of solvent.

Papers, plastic film bases, glass plates, metal plates, etc. are usable as supports. However, photographic papers and plastic coated papers are preferred because the resulting light-sensitive photographic material can produce a clear image with high resolution and high density. A clear transparent image can be obtained by coating the solution onto a photographic film base. The amount of a lightsensitive layer to be coated on a support generally will be 23,u. in thickness. Higher light-sensitiveness and higher density can be obtained by increasing thickness of the said layer.

A light-sensitive, photographic material of the invention is subjected to printing operation by exposing through an image-bearing original to light, whereby a clear image is developed through color change or decolorization. Light sensitiveness of the material is several to several ten times high as compared with that of a commercially available diazotype copying sheet. If necessary, the enlarged image of an original can be obtained :by means of a suitable apparatus. The printed image is stable, but it should be fixed because said image can not be stored in a light place unless the light sensitiveness remaining at the nonexposed area is nullified. Fixation can be effected by heating, after printing, the light-sensitive, photographic material so to stabilize the residual photo-activator and color modifier. Alternatively, the said material can be treated with a solvent thereby to remove the above-said components. Thermal fixation is conveniently carried out by passing the photographic material between hot rolls having a surface temperature of to C. Solvent fixation can be made by using a suitable solvent which does not dissolve the remaining and resulting coloring components but dissolve the photo-activator. For example, an equal amount mixture of ethyl acetate and cyclohexanone is most preferred for a nega-posi type lightsensitive, photographic material in which the photoactivator is the compound (3) as mentioned before and the color modifier is diphenylamine. Trichlene, methanol, acetone and the like solvent are not suitable for the same photographic material because these solvents dissolve the coloring matters as formed. It should be noted that a solvent used for solvent fixation is properly selected depending on the components of a light-sensitive photographic material. If a suitable solvent is used, solvent fixation will be complete within 0.5-2 minutes.

Now the following examples will be given to show the present invention in detail.

EXAMPLE 1 A photographic paper is coated with polyvinyl alcohol having a polymerization degree of about 600 at thickness of 1-1.5 g./m. To the photographic paper thus surfacetreated, a light-sensitive solution is coated at the amount of 20 cc./m. under safe yellow light, said solution having the following formulation:

Hexabromodimethyl sulfone-S g. Diphenyl amine-5 g.

Acetyl cellulose-10 g. Acetone-30 cc.

Benzene-70 cc.

EXAMPLE 2 A light-sensitive, printing-out type photographic maerial is prepared in the same manner as in Example 1, H112 using p,p'-benzylidene-bis (N,N-dimethyl aniline) (i.e. .euko compound of Malakite Green) instead of the diuhenylamine used in Example 1. The photographic maerial yields a clear bluish green image on White background by treating said material in the same manner as [1 Example 1. This photographic material is of the nega- IOSi type, and so it can provide either a positive image r a negative one depending on whether the used original s a photographic negative or positive respectively.

EXAMPLE 3 A light-sensitive solution containing a sensitizer is preared, the formulation of which is as follows:

exabromodimethyl sulfone-S g. Diphenyl aminel g. x-Dimethylaminobenzaldehyde-1 g. Dellulose acetate butyrate10 g. \cetone30 cc.

Benzene-J0 cc.

lhe light-sensitive solution is coated at the amount of 20 :c./m. onto a photographic cellulose triacetate film base )f 0.14 mm. thick under yellow safe light in the manner mown per se. The coated film base is then dried in a lark room at a temperature of less than 60 0., thereby o obtain a light-sensitive printing-out type photographic material which can produce a satisfactorily dense, clear :olor image by one-second exposure when printing is dfected by using the same light source as in Example 1.

EXAMPLE 4 To the same photographic paper as used in Example 1, a ight-sensitive solution is coated at the amount of 15 :c./m. the formulation of said solution being as follows:

['ribromomethylphenyl sulfone-S g.

LN-dihydroxyethylaniline5 g.

t/laleic anhydride1.5 g.

laran F 220 (vinyliden chlorideacrylonitrile copolymer resin)-5 g.

rcetone100 cc.

lfter drying, a desired light-sensitive, printing-out type thotographic material is obtained. This material is exosed in the same manner as in Example 1, whereby a lear blue image is developed on white background. By assing the material between hot rolls having a surface emperature of 150 C., the formed image is fixed. The mage is so stable that no appreciable change is observed :ven by exposure to intense ultraviolet irradiation.

EXAMPLE 5 A light-sensitive, printing-out type photographic mateial is prepared by coating a light-sensitive solution at the amount of 20 cc./m. onto a photographic paper, the formulation of said solution being as follows:

2,5-dimethyl 4 chlorophenyl-trichloromethyl sulfone- Diphenyl amine10 g.

Acridine Orange0.1 g.

Maleic anhydride1.5 g.

Polyvinyl acetate-2 g.

Acetone-1OO cc.

The photographic material which contains the dye as color sensitizer has a broad sensitivity to cover a visible light region and is more sensitive by ten times than the photographic material of Example 1. The photographic material of this example can provide a clear blue image when imagewise exposure is made at a distance of 30 cm. for 15-20 seconds by means of a slide projector bearing a photographic negative and using a tungsten lamp as light source. Fixation is achieved by passing the material between hot rolls having a surface temperature of C., thereby to give a stable image with good resolution.

EXAMPLE 6 A light-sensitive, bleaching-out type photographic material is prepared by coating a light-sensitive solution at the amount of 16 cc./m. onto a photographic paper, the formulation of said solution being as follows:

Hexabromodimethylsulfoxide10 g.

2 Carbostearylamino-4-pdihydroxyethylaminophenylimino-naphthoquinone1 g.

Cellulose acetate-5 g.

Acetone-7O cc.

Methanol-30 cc.

The photographic material is of the posi-posi type, and it can give a clear bluish green image when said material is exposed through an original to irradiation at a distance 30 cm. from a 300 watt-xenon lamp for 2 minutes. The resulting image can be fixed to a stable image with good resolution by immersion with an equal mixture of ethyl acetate and cyclohexane for one minute.

EXAMPLE 7 A light-sensitive printing-out type photographic material is prepared by coating a light-sensitive solution at the amount of 20 cc./m. onto a photographic paper, the formulation of said solution being as follows:

Pentabromodimethyl sulfoxide-IO g. N-vinyl carbazole10 g.

Cellulose acetate-5 g.

Acetone-50 cc.

Benzene-50 cc.

The photographic material when exposed to light gives a pale pellow image, the density of which can be remarkably increased by thermal fixation. For example, the photographic material after printing is passed between hot rolls having a surface temperature of 150 C. thereby to have a density increase up to five timeslf such density increase is taken into consideration, the photographic material of this example is more sensitive by about 50100 times than that of Example 1. Resolution of the resulted image also is excellent.

What is claimed is:

1. A light-sensitive, photographic material which comprises a support bearing a light-sensitive layer comprising a photo-activator capable of generating a free radical by the action of light and an organic compound which reacts with the said free radicals to produce a color change, said photo-activator being a compound the general formula (wherein is hydrogen, chlorine or bromine; Y is hydrogen, chlorine or bromine; Z is chlorine or bromine; and R 9 is non-substituted or substituted aryl group, heterocyclic group or a group R1 CR2 in which R R and R individually are hydrogen, chlorine or bromine.

2. A light-sensitive, photographic material as claimed in claim 1, further comprising an optical sensitizer selected from the group consisting of acridine dyes, cyanine dyes, mellocyanine dyes and styryl dyes.

3. A light-sensitive, photographic material as claimed in claim 1, further comprising a chemical sensitizer selected from the group consisting of benzaldehyde, dimethylaminobenzaldehyde, ortho-phthaldehyde, salicylaldehyde, thiosalicylaldehyde, anisaldehyde, vanilline, phenyle acetaldehyde, o-chlorobenzaldehyde, ascorbic acid, benzaldehyde sulfonate, 4-methylquinoline N-oxide, 2,2'-dipyridine N-oxide disulfide and quinoline N-oxide.

4. A light-sensitive, photographic material as claimed in claim 1, further comprising a thermal fixing agent selected from the group consisting of phthalic anhydride, malic anhydride, succinic anhydride, benzoic acid, phenylacetic acid, phenoxyacetic acid, phthalaldehydic acid, palmitic acid and stearic acid.

5. A light-sensitive photographic material as claimed in claim 1, wherein the photo-activator used is at least one compound selected from the group consisting of hexabromodimethyl-sulfoxide, pentabromodimethylsulfoxide, hexabromodimethyl sulfone, trichloromethylphenyl-sulfone, tribromomethyl-phenyl-sulfone, trichloromethyl-p-chloropheny1-sulfone, tribromomethyl pnitrophenyl-sulfone, 2-trichloromethyl-benzothiazolyl-sulfone- (2), 4,6 dimethylpyrimidyl 2 tribromomethyl-sulfone, tetrabromodimethyl-sulfone, 2,4-dichlorophenyl-trichloromethyl-sulfone, 2-methyl-4-ch10rophenyl-trichloromethylsulfone, 2,5 dimethyl 4 chlorophenyl-trichloromethyl sulfone, 2,4-dichlorop11enyl-tribromomethyl-sulfone and bromomethyl-dibromomethy1-sulfone.

6. A light-sensitive, photographic material as claimed in claim 1, wherein the photographic material is of the printing-out type (nega-posi system) and the organic compound used is a compound selected from the group consisting of diphenyl amine, dibenzyl amine, triphenyl amine, N,N-diethyl aniline, N,N-dimethyl aniline, N- hydroxy-N-ethyl aniline, dibenzyl aniline, o-aminodiphenyl amine, p-hydroxydiphenyl amine, N-vinyl carbazole, 2-pheny1 indolidine, N,N-dihydroxyethyl aniline, N,N-dipheny1-p-phenylene diamine, N,N-dihydroxyethylm-toluidine, a-naphthyl amine, p-dimethylamino-benzaldehyde, 3-aminoquinoline, indole, salicylidene-p-toluidine, salicyclidene p-chloroaniline, cyanomethylene-4-quinolyl- Z-naphthalene, 3-phenyl-ind0le, a-diethylaminopyridine, p,p-methylene bis-aniline, p,p'-methy1ene bis-(N,N-dimethylaniline), p,p' -benzylidine bis-(N,N-dimethylaniline), p,p',p-methylidine tris-(N,N-diethylaniline), p,p'- hydroxy-methylene bis(N,N-dimethylaniline), p,p'-(dimethylamino) diphenyl amino, p,p'-aminomethylene-bis (N,N-dimethylaniline), p,p'-(o"-chlorobenzylidene) bis (N,N-dimethylaniline), p,p'-(p"-aminobenzy1i dene) bisaniline, p,p-(p"-amino-m"-methylbenzylidene) bis(N- phenylaniline), 1,1 bis(p-dimethylaminophenol) p'-dimethylaminophthalein, 3,6 bis(diethylamino)spiro (phthalein 1,9 xanthene), 3,6 bis(diethylamino)-9-(pdimethylaminophenol)xanthene, 1,1-bis(p-dimethylaminophenol) p dimethylaminophthalane, 1,1 bis(p-aminophenol) p-aminophenol-phthalane, 10-benzoy1-3,7-di(pdimethylamino) phenothiazine, 10 cinnamoyl-3,7-di(pdimethylamino) phenothiazine and 3 diethylamino-7- aminophenoxazine; the quarternary salts of Z-methylbenzthiazole methyl iodide, 2-methylbenzthiazole ethyl bromide, quinardine methyl iodide, 2,5-dimethylbenzthiazole methyl-p-toluenesulfonate and 2,5,6-trimethylbenzthiazole butyl iodide; as well as 4-methylquinoline N- oxide, 2,2'-dipyridine N-oxide disulfide and quinoline N- oxide.

7. A light-sensitive photographic material as claimed in claim 1, wherein the photographic material is of the bleaching-out type (posi-posi system) and the organic compound used is a compound selected from the group consisting of Orlamin (C.I. 41000), Victoria Blue (0.1. 44045), Victoria Blue R (CI. 44040), Brilliant Lowdurine Blue (C.I. 42565), Benzoyl Methylene Blue, Cinnamoyl Methylene Blue, p-Anisoyl Methylene Blue, New Methylene Blue (CI. 51195), Nile Blue A (CI. 51180), Ephitenew Blue (01. 51185), Rhodamine B (CI. 45170), Rhodamine 3B (CI. 45175), Rhodamine 12 GM (CI. 45310), Sudan Brau G (01. 61525), Sudan Blue GN (CI. 61520), Celliton Blue (CI. 64500), 4-p-diethylaminophenylimino-naphthoquinone, 2-carboxyanilino-4- p diethylaminophenylimino naphthoquinone, 2 carbostearylamino 4-p dihydroxyethyl-aminopheny-liminonophthoquinone, p methoxybenzoyl p-diethylamino-omethylphenylimino acetanilide, cyano-p-diethylaminophenylimino-acetanilide, 1-phenyl-3-methyl 4-p-diethylaminophenylimino S-pyrazolone and l-B-naphthyl-B- methyl-4-p-diethylaminophenylimino-5-pyrazolone.

OTHER REFERENCES Soviet Inventions Illustrated, Preparation of Di-(Trichloro-methyl)-Sulphone, Pub. 3-1966, pp. 5, 16.

NORMAN G. TORCHIN, Pn'mary Examiner WON H. LOUIE, JR., Assistant Examiner US. Cl. X.R. 96-48 

